Disparities in limb salvage procedures may be driven by SES, access to high-volume hospitals

Jan 29 2011

Researchers from Brigham and Women's Hospital at Harvard Medical School in Boston, MA have published a study in the February Journal of Vascular Surgery® stating that disparities in limb salvage procedures may be driven by socioeconomic status (SES) and access to high-volume hospitals.

Senior-author Louis L. Nguyen, MD, MBA, MPH, from the Hospital's division of vascular and endovascular surgery as well as the Center for Surgery and Public Health explained that 958,120 cases containing lower extremity revascularization (LER) or major amputation were reviewed. Data for patients with critical limb ischemia (CLI) also were collected. All patients were 21 years or older and the data was taken from the 2003-2007 Nationwide Inpatient Sample. Findings showed an increased risk of major amputation among minority patients, while adjusting for income, insurance status, hospital-level factors and LER volume.

Several indicators of low SES were clustered by demographic group. Compared with Caucasian patients, Native Americans were the most likely to have income in the lowest quartile. Similar lower median income was seen for Black and Hispanic patients. Non-whites were more likely to be on Medicaid and had lower income than patients with Medicare.

"Minority patients tend to have more comorbidities including diabetes, peripheral artery disease (PAD) and renal failure that influence treatment options as they are more likely to receive care at low-volume and potentially under-resourced hospitals," said Dr. Nguyen. "These factors, independently and in combination, are associated with a greater likelihood of major amputation.

This outcome profoundly impacts the function of CLI patients and their quality-of-life. Our data are similar to other reports that patients with CLI who present to higher volume hospitals are more likely to undergo a limb salvage procedure."

Researchers added that higher-volume hospitals may have more fellowship-trained vascular specialists, established protocols for perioperative care of patients with CLI, and greater access to angiography facilities. Patients who did not have primary payer insurance also had lower income than those with Medicare and were more likely to be minorities. In this current study, non-insurance cases included 24 percent of CLI patients. Demographic trends showed factors associated with amputation (vs. LER) also included older age and male gender.

Compared with patients with the highest income, patients in the lower three income quartiles were at 11 to 34 percent higher odds of undergoing major amputation. Private insurance remained negatively associated with major amputation and patients with Medicaid were at slightly increased odds of major amputation with those with Medicare.

In comparison to patients at the highest volume centers, patients at the lowest volume centers were at 15.2 times higher odds of undergoing major amputation. Patients in the second quartile were also at significantly increased odds of undergoing major amputation and those at hospitals in the third quartile were at 77 percent higher odds of undergoing major amputation compared to those at the highest volume.

"Our findings suggest there are gaps in access to care despite controlling for hospital level factors and procedural volume," added Dr. Nguyen. "Addressing SES, hospital factors and the inverse relationship between LER procedure volume and risk of major amputation for CLI, highlights potential solutions for disparities related to hospital-level factors. Also increasing state and local funding to facilities that provide care to patients at high risk for major amputation may improve professional resources."

Dr. Nguyen added that further analysis of datasets that contain information on referral patterns and utilization of outpatient health care could guide potential interventions which target patients at high risk for PAD and major amputation. He noted that this information also could lead the way for implementing screening protocols focused on risk factor modification and appropriate early vascular surgery referral pathways.

"Given the highly positive impact of preoperative angiography on the likelihood of undergoing a LER procedure, studying the factors influencing the clinical decision to evaluate revascularization options may illustrate reasons for the less frequent use of angiography in certain patient populations and help to more widely implement standard diagnostic protocols," concluded Dr. Nguyen. "Further exploration of these potential mechanisms of disparities both at the patient and the hospital levels may improve limb salvage for the vulnerable population."